FOA, there is no Pancolar 55/1.8 , its just 50/1.8
Now for the use of it, I think none of the 50/55 is actually long enough for proper. One might want to look into getting something along the 75-90 range even for digital. That said, if you are into these 2, I say the Takumar 55/1.8 is more all rounder !!